RLS11 — CRS definition for pose information

Explicit CRS definition for pose information is necessary. Especially, the relation between pose CRS and position CRS and its semantics shall be defined

In ISO 19111 which RLS is based on, relation between CRSs is defined by using
datums and transformations. In this sense, in order to represent pose information,
we need to define a new datum. However, we found that generally this is not
appropriate as identifying pose is tightly related to its associated position. In the
original idea of CSs and CRSs in ISO 19111, CSs implicitly hold transformations
that can in most cases be identified trivially. However, when extending this to
pose, the necessary transformation becomes not so trivial and thus a much
explicit mean for specifying the associated transformation, in combination with
‘position’ transformation, becomes necessary. Moreover, it is only a special case
that position and pose information (or transformations) are mathematically
independent, i.e., where transformations for position and pose can be defined
separately. Therefore, position and pose information shall be represented in
combination inseparable from each other. One way is to represent position/pose
as a generalized position which is a set of parameters for a transformation that
defines a mapping from the base CRS to the resulting position/pose. In this
sense, what is called a CS or CRS shall be represented as a transformation ,and
coordinate values which we normally call ‘position’ are parameters for the
transformation. (for detailed discussion, see [Noda2010])
[Noda2010] Itsuki Noda, Shuichi Nishio, Takashi Tsubouchi, Takeshi
Sakamoto and Satoshi Tadokoro, "Mathematical Framework for Localization
Information Coordinate Reference System for Robotics", in Proc. of Int.
Workshop on Standards and Common Platform for Robotics 2010 (SCPR
2010), 2010.
This notion is mathematically much rigid. However, it requires complete
reconstruction of the ISO 19111 which RLS is based on. As this is not something
to be discussed here, here we propose a much modest modifications. In the
future, this shall be discussed in ISO/TC 211.
Followings are the modified points: - Add non-normative reference

• Add background description (section 7.3 – Architecture Package)
• Add two classes (PoseType and PositionPoseCRS) in Architecture Package
• Define frequently used pose types
• Modify section 7.4.1 – Common Data Format to use the defined pose types and
  remove figures/descriptions that also appear in previous description
• Modify C++ PSM accordingly